This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A121000 #10 Aug 30 2019 03:46:26 %S A121000 1,325,52651,34117853,5527092193,596925956851,96702005009873, %T A121000 125325798492795551,60908338067498638501,19734301533869558876755, %U A121000 3196956848486868538038509,2071628037819490812648983225 %N A121000 Numerators of partial sums of Catalan numbers scaled by powers of 1/18^2 = 1/324. %C A121000 Denominators are given under A121001. %C A121000 This is the fourth member (p=3) of the first p-family of partial sums of normalized scaled Catalan series CsnI(p):=sum(C(k)/L(2*p)^(2*k),k=0..infinity) with limit L(2*p)*(F(2*p+1) - F(2*p)*phi) = L(2*p)/phi^(2*p), with C(n)=A000108(n) (Catalan), F(n)= A000045(n) (Fibonacci), L(n) = A000032(n) (Lucas) and phi:=(1+sqrt(5))/2 (golden section). %C A121000 The partial sums of the above mentioned first p-family are rI(p;n):=sum(C(k)/L(2*p)^(2*k),k=0..n), n>=0, for p=0,1,... %C A121000 For more details on this p-family and the other three ones see the W. Lang link under A120996. %C A121000 The limit lim_{n->infinity} r(n) = 18*(13 - 8* phi) = 18/phi^6 = 1.003105620014 (maple10, 15 digits). %H A121000 W. Lang: <a href="/A121000/a121000.txt">Rationals r(n), limit.</a> %F A121000 a(n)=numerator(r(n)) with r(n) := rI(p=3,n) = sum(C(k)/L(6)^(2*k),k=0..n), with Lucas L(6)=18 and C(k):=A000108(k) (Catalan). The rationals r(n) are given in lowest terms. %e A121000 Rationals r(n): [1, 325/324, 52651/52488, 34117853/34012224, %e A121000 5527092193/5509980288, 596925956851/595077871104, ...]. %K A121000 nonn,frac,easy %O A121000 0,2 %A A121000 _Wolfdieter Lang_, Aug 16 2006